Materials Data on La2HfSe5 by Materials Project

Abstract

La2HfSe5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. La3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of La–Se bond distances ranging from 3.07–3.24 Å. Hf4+ is bonded to seven Se2- atoms to form distorted edge-sharing HfSe7 pentagonal bipyramids. There are a spread of Hf–Se bond distances ranging from 2.69–2.87 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent La3+ and two equivalent Hf4+ atoms to form distorted SeLa2Hf2 trigonal pyramids that share corners with four equivalent SeLa4Hf square pyramids, corners with four SeLa4Hf trigonal bipyramids, corners with six equivalent SeLa2Hf2 trigonal pyramids, an edgeedge with one SeLa4Hf square pyramid, edges with four SeLa4Hf trigonal bipyramids, and an edgeedge with one SeLa2Hf2 trigonal pyramid. In the second Se2- site, Se2- is bonded to four equivalent La3+ and one Hf4+ atom to form distorted SeLa4Hf trigonal bipyramids that share corners with five equivalent SeLa4Hf square pyramids, corners with five SeLa4Hf trigonal bipyramids, corners with four equivalent SeLa2Hf2 trigonal pyramids, edges with two equivalent SeLa4Hf square pyramids, edges with four equivalent SeLa4Hf trigonal bipyramids, and edges with four equivalent SeLa2Hf2 trigonal pyramids. In the third Se2- site, Se2- is bonded to four equivalent La3+ and one Hf4+ atom to form distorted SeLa4Hf square pyramids that share corners with nine SeLa4Hf trigonal bipyramids, corners with eight equivalent SeLa2Hf2 trigonal pyramids, edges with two equivalent SeLa4Hf square pyramids, edges with three SeLa4Hf trigonal bipyramids, edges with two equivalent SeLa2Hf2 trigonal pyramids, and a faceface with one SeLa4Hf trigonal bipyramid. In the fourth Se2- site, Se2- is bonded to four equivalent La3+ and one Hf4+ atom to form distorted SeLa4Hf trigonal bipyramids that share corners with four equivalent SeLa4Hf square pyramids, corners with five SeLa4Hf trigonal bipyramids, corners with four equivalent SeLa2Hf2 trigonal pyramids, an edgeedge with one SeLa4Hf square pyramid, edges with four equivalent SeLa4Hf trigonal bipyramids, edges with four equivalent SeLa2Hf2 trigonal pyramids, and a faceface with one SeLa4Hf square pyramid.